Composite Digital Animation Techniques used in Yeowoobi (여우비)

August 19, 2010

There is a fansite dedicated to a Korean animated film titled Yeowoobi, where you can find production notes on the actual making of the movie. I like how the images they provided speak for themselves, but for more clarity, I summarised some notes in this post along with the said visual references for those interested in more technical aspects of animation. Hope you find it somewhat amusing and educational.

Compositing 4 elements to form an image

When drawing backgrounds through conventional methods, each background template would be coloured individually. Achieving high quality backgrounds this way would be difficult without many experienced animators (especially in Korea), so the staffs looked for an alternate approach.

What is a picture made of? Lines, texture, colours, lighting/shading. So these elements were separated into 4 different layers and worked on very quickly, before blending on top of each other to create more detailed image. I found this part interesting because we go through similar process when drafting 2D architectural drawings (i.e. CAD lines->fills->other overlaying effects including texture/lighting).

This has the benefit of separating each elements that can be saved to library as source files that can be accessed by all team members. If you need to draw a tree for different background, it’s possible to make small modifications of an already saved twigs/leaves/branches to make a slightly different looking tree without drawing everything again! (at this point I felt they were being slack but hey…)

People say ‘beautiful pictures must sing’, but it’s undesirable for elements other than the characters to make too much noise (not sure if I agree 100%). Object and spatial qualities must hide its presence and support the characters. So when working on the design of bathroom for example above, things like character’s feelings and how the space and objects can best help portray that, these issues are considered as the image is being developed. See the above development for example. 1400 background cuts were drawn by 6 animators over 9 month, which is about one person completing one background image in one day.

But one of the best things about the Yeowoobi is that, in many cases, backgrounds are fleshed out as virtual world instead of static 2D image. What this means is that when characters move through their surrounding, the world rotates and turns, evoking more realistic sense of us actually ‘being’ in that fictional world. This is possible by first modelling objects in modelling program, and have a ‘camera’ to ‘walk’ around the set. By doing this we get to explore this three-dimensional set from the perspective of a walking camera (or in this case, walking character).

But the challenge was coming up with 3D renderings that had the looks and feelings of 2D backgrounds, so they feel more like hand-drawn watercolour paintings than clean and photorealistic objects. In the end, it was possible to render 3D backgrounds (like the one above) to look like 2D through a simple process below.

The solution was to use the same approach they used for 2D backgrounds where each 3D object would be worked through 4 different stages (one for each layer – line, texture, colour, shading/lighting). Since lifework and shadings were almost done automatically once you give them shape and form, it was possible to spend more time on changing layers of colour and texture to feel more rich and stimulating, and more like 2D.

Above drawing is an example of conte (storyboarding). Self-explanatory I suppose, but it has basic details for the staffs for each cut (the picture above includes notes like “here dust will arise like mist”, “and then the stairs will shake”). This stage is extremely important because it’s basically a blueprint for how characters should move, what kind of colours and feelings will the background exhibit, etc. If conte is not properly done it will severely hinder the production schedule when the staffs go back and modify any overlooked errors.

So ultimately Yeowoobi is predominantly made in 3D in contrast to conventional 2D animation. Instead of completing most work in 2D drawings and using 3D layouts as enhanced effects, Yeowoobi mainly used 3D modelling (90%) as well as layouts to emulate more cartoony (and less photorealistic as expected from most 3D) feelings of traditional 2D animation. The biggest advantage of this technique was the ability to gain real-time feedback by running walking test, before deciding on the cinematography/general direction and finalising the drawings through more detailed colouring/texturing. This is something 2D animation production can not do since you can not test 2D animation without actually having to draw every cut.

Colour was another important visual aspect of the movie. When travelling many places one might notice different colours of sky. The city of Seoul has a unique colour of sky. Unfortunately, sky has always been portrayed as bright blue ever since we imported American and Japanese ways of animation. So a different colour was chosen, something that’s still bright, a refined and dignified colour that better suits Korea’s climate and culture.

The colour blue was also reserved for the colour of sacred lake. There are cinematic moments in the movie when the character Yobi enters the lake, and the world around her will be blue. This lake is symbolic of our first love we feel as child, the most pure and sacred form of love where elements of lust and possession are non-existent. To express this, blue is presented as deep and warm as possible to evoke innocent and youthful aspects of love.

As for the actual movie, I found it much weaker than the director’s previous work of art, My Beautiful Girl Mari. Still, it’s an ‘ok’ family animated movie that enchanted many viewers at the time (2005). The techniques they are using isn’t anything new, but something quite rare to see in Korean animation industry at such a large scale, and maybe for that alone the movie deserves some merit. Also, the main character’s very cute.

You know, considering that I’m burned out from anime, I need to check out what Korea has to offer to the world of animation.

The animation techniques here are pretty interesting due to the speed and quality of the final product. I’ve used similar techniques in drawing courses, except I didn’t use linework, only layers of progressively darker colors.

If you want to watch more Korean animations, I’d say start off with great fun action (and filthy) movie Aachi wa Ssipak, I’m sure you’ll enjoy it. If you feel like more mature, witty and down to earth story, go with Life is Cool. For more surreal and artistic work (but very slow), Mari Iyagi. Or Oseam for a touching drama based on Korean folktale set on beautiful Korean landscapes.

Very insightful post. I’ve often speculated on some of the techniques that could be utilized to create photorealistic backgrounds in several animated works by studios that have a lot of heavy Korean outsourcing, such as P.A. Works, but it’s good to see some illustration of the technique.

Korea at the moment seems to be, if not exactly a leader, at the very least the go-to guy for this sort of rapid 3d paint-over style of animation at present. You can recognize these techniques at work in almost every single series by P.A. Works so far – consider the trees in the opening sequences of True Tears, or the many urban landscape shots in Angel Beats! or CANAAN.

Haven’t seen much of P.A. Works but yea Koreans are being outsourced a lot by Japanese mostly for grunt works like ‘please put all the trees here’. Kinda sad haha. But sometimes Korean companies are given creative controls in key animations, as it was the case for Avatar: Last airbender I think, so that’s good.